Rotary pump



- G. B. PETSCHE.

ROTARY PUMP.

APPLICATION FILED OCT. 6, 1920.

Patented Nov. 22, 1921.

A TTORNE Y .HTE gTAT PATNT FE.

GUSTAV B. PETSGEE, 0F YONKERS, NEW YORK.

ROTARY PUMP.

Specification of Letters Patent.

Patented Nov.122,1921.

Application filed October 6, 1920. Serial No. 415,142.

beinghad to the-accompanying drawings,

which form a part thereof.

My invention relates to rotary compressors of the type in which the: piston consists of an eccentric ring actuated by an eccentric on the driving shaft and provided with an extension which forms. a partition between the ports. The object of my'inventionis to provide such a pump with a delivery valve actuated to open by the building up or pressure in the cylinderand actuated to close by a positively driven cam.

The nature of my'improvements will be best understood as described in connection with the drawings in which they areillustrated as applied to a grid iron slide valve and in which 5 Figure 1 is a side elevation taken on the section line 1-'1 of Fig. 2.

Fig. 2 is a front view partly in section on the broken line 2--2 of Fig. 1.

Fig. 3 is a plan view partly in section on the line 3-3 ofFig. 1. 1

Figs. 4 and 5 are vie ws showing modifications of the cams and cam actuated devices.

A and A are two twin pump cylinders formed in the same casing having face plates A and A A indicates the cylindrical periphery of one of the pump chambers cutaway from a to d to give clearance for the motion of the piston extension. B is the bearing for the swivel block: B the admission chamber and B the receiving chamber.

G is adelivery passage-leading from the delivery-end of the pump chamber to the receiver B C being a port leading into the pump chamber and C the port leading into the receiver. D is the drivingshaft to which are attached'eccentrics as indicated at D. E indic'at'es the eccentric ring piston having an extension here shown as the slideF extending from one side-of it, the slide in the construction illustrated having a passage F communicating with the admission chamber B and with the port F opening into the pump 0 linder and arranged to be closed by the si es of the swivel block when the piston is not in contact with the periphery of the cylinder.

- a cam contacting roller H G is a valve .casing or bushing fitting in the. chamber C and having a grid iron valve seat indicated at G. H is a grid iron valve seated on this seat and having a stem H to which, as shown, is secured a iston H and is a cylinder connected at one side with the ort I leading as shown from the port and connected on its other side by a port I with the receiver. J is a cam shaft having secured to in cams as indicated at J, the shaft J being driven through gear wheels K, K, shaft K and gear wheels K K the last of which is secured'to the rear end of the driving shaftat. the pump. Preferably the cam shaft gearing-s are inclosed by casings indicated at L, so as to avoid the necessity of additional stufling boxes with theirpossible leakage which is most objectionable where. poisonous gases are to be compressed.

These casings should be charged with oil. 0 indicates the swivel block.

In. Fig. 4 the. cams indicated at M are secured to arms M extending out from the rock shaft M actuated through a lever arm M and connecting rod M with a crank M on the shaft D and in Fig. 5 the cams indicated at N, N, are attached to a slide N actuated through a link N and lever N by some connection with the driving shaft not shown.

In operation the gas in the admission chamber B passes through the passage F in the slide F and enters the receiving side of the pump chamber through the port'F this port being closed by the surface of the swivel block at one period in the motion of the piston which coincides with the period when the piston is passing from contact at a to contact at a. These features of conthe compressor is propelled toward the delivery side of the cylinder by the piston the pressure will build up in the port C and on the under side of the grid iron valve H which is normally closed and held to, its seat by the pressure in the receiver B". As the pressure builds up on the lower side ofthe valve it is communicated to theleft hand side of the cylinder I through the port I while .the right hand side of the cylinder is in communication with the cylinder B through the port I At the time when the pressure on both sides of the valve is about equal the pressure on the left of piston N will open the grid iron valve permitting the fluid to flow into the receiver. The form and motion of the cams indicated at J is such that they will positively close the valve at theend of the compressing cycle and the piston. This is very important irrespective of the kind of valve used or the means employed to open it, in view of the high speed with which compressions of the kind indicated are operated.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is: i

1. In combination with a rotary compressor having a rotary eccentric ring piston provided with an extension forming a partition between the admission and delivery ports, a valve seat in the delivery port, a delivery valve operating with said seat to open and. close the port, a cylinder and piston for actuating said valve to open it, said cylinder being connected to the delivery side of the compressor and operating to open the valve when the pressure in the compres sor attains a definite ratio to the. pressure in the receiver, and a cam operating synchronously with the driving shaft of the compressor and formed to close the valve at the end of the compression 0 cle of the piston.

2. In combination wit arotary compressor having a rotary eccentric r1ng piston provided with an extension forming a partition between the admission and delivery ports, a grid 'valveseat located in the delivery port, a grid valve movable on said seat, a cylinder and piston for actuat ng said valve to open it, said cylinder being connected to the delivery side of the compressor and a cam operating synchronouslywith the driving shaft and formed to close the valve at the end of the compression cycle of the piston. I

3; In combination with a rotary compressor having a rotary eccentric ring plston provided .with an extension forming a partition between the admission and delivery ports, a grid valve seat located in the delivery port, a grid valve movable on said seat, a cylinder and piston for actuatmg livery port, a grid valve movable on said seat, a cylinder and piston for actuating said valve to open it said cylinder being connected to the delivery side of the compressor, a cam for closing the valve, gears'for operatively connecting the cam with 'the driving shaft and a tight casing inclosing said gears.

5. In a rotary pump having a rotary eccentricring piston and a slide extending from said piston through a swivel block, a delivery passage extending from the cylinder to a receiver a grid valve seat in said passage a grid valve movable on said seat to open and close the passage, a cylinder connected at opposite ends to the delivery side of the pump and to the receiver, a piston working in said cylinder and operatively congnected to the valve and a cam actuated synwith the driving shaft of the chronousliy operatlng on the valve to close it pump an .at the end of the compression cycle of the pum%.

6. n a rotary pump having a rotary eccentric rin piston and a slideextending from said piston through a swivel block, an admission port and means for closing said port during the period when the piston is not in contact with the periphery of the cylinder, a delivery passage extending from the cylinder to a receiver, a grid valve seat in said passage, a grid valve inombleon said seat to open and close the passage, 0. cylinder connected at opposite ends to the delivery side of the pump and to the receiver,

a piston working in said cylinder and operatively connected to the valve and a cam actuated synchronously with the driving shaft of the pum and operating on the valve to close it at t e end of the compression 0 cle'of the um y p (.iITSTAV B. PETSCHE. 

